SEMICONDUCTOR DEVICE AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To manufacture a power MOSFET of low ON-resistance and high breakdown strength without greatly increasing the number of processes. SOLUTION: An n- type epitaxial Si layer held between trenches 3 is changed to a semiconductor structure consisting of n-type pillar layer 5/p-type pillar layer 4/n-type pillar layer 5 arranged transversely, which practically plays the same role as a super junction structure, by implanting As and B to a side surface of the trench 3 by using a rotational ion implantation method and using the difference in diffusion coefficient.